JP2008129377A - Substrate for electrooptical device, electrooptical device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce, e.g., cross talk to be generated when a liquid crystal device displays an image. <P>SOLUTION: A third interlayer insulating film 43 is formed between a data line 6a and a pixel electrode 9a and a part thereof extended to a region R where the data line 6a and the pixel electrode 9a are superposed is formed so as to be thicker as compared with the other part. To put it concretely, a projecting part 43a is formed as the part extended to the region R in the third interlayer insulating film 43. According to the projecting part 43a, the distance between the pixel electrode 9a and the data line 6a is widened as compared with the case where the third interlayer insulating film 43 is formed as a uniform insulating film, and parasitic capacity generated by using the pixel electrode 9a and the data line 6a as capacitance electrodes is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of an electro-optical device substrate applied to a liquid crystal device such as a light valve used in a liquid crystal projector, an electro-optical device including such an electro-optical device substrate, and an electronic apparatus.

In a liquid crystal device which is an example of this type of electro-optical device, a large number of scanning lines and data lines arranged vertically and horizontally in a display area composed of a plurality of pixels, and a large number of pixel electrodes corresponding to the intersections thereof. Is provided on the substrate. Such a liquid crystal device employs, for example, an active matrix driving method by TFT (Thin Film Transistor) driving, and in addition to a wiring portion such as a scanning line, a sample hold circuit, a precharge circuit, a scanning line driving circuit, data Various peripheral circuits having TFTs as components, such as line drive circuits and inspection circuits, are provided on the substrate.
Such a liquid crystal device controls the orientation of the liquid crystal according to an image signal supplied to the pixel electrode of each pixel portion via a peripheral circuit during its operation, and in a display region in which a plurality of pixel portions are arranged. Display an image.

  On the lower layer side of the pixel electrode, a non-opening region that separates the opening region of the pixel (that is, the region through which light is substantially transmitted) from each other, such as a metal material such as aluminum, or a semiconductor material such as polysilicon. Wiring portions such as data lines and scanning lines are formed using a conductive material that does not transmit light. These wiring sections relay various signals such as scanning signals and image signals supplied from the peripheral circuit section to each pixel section.

  In a liquid crystal device, when a wiring portion such as a data line and a conductive portion such as a pixel electrode overlap with each other, a parasitic capacitance is generated between the conductive portions, and the display performance of the liquid crystal device is deteriorated. . More specifically, for example, the potential of the pixel electrode varies due to the parasitic capacitance described above, and the alignment control of the liquid crystal according to the image signal is performed between the pixel electrode and the counter electrode facing the pixel electrode. May not be performed.

  As an example of means for solving such a problem, Patent Document 1 discloses that a parasitic layer generated between a pixel electrode and a data line is reduced by providing a shield layer made of a conductive material between the data line and the pixel electrode. The technology to do is disclosed.

JP-A-10-39336

  However, according to the technique disclosed in Patent Document 1, an additional capacitance is generated between the shield layer and the data line, and a writing time for writing an image signal to the pixel portion via the data line is delayed. Such a delay in writing time causes display defects such as so-called crosstalk.

  On the other hand, since an insulating film is usually formed between the pixel electrode and the data line, it is considered that the parasitic capacitance can be reduced by increasing the film thickness of the insulating film. A contact hole for electrically connecting various wiring portions and circuit portions along the vertical direction on the TFT array substrate is formed in a portion extending to another region different from the region where the electrode and the data line overlap each other. . Therefore, when the thickness of the insulating film is increased, the ratio of the depth to the opening diameter of the contact hole is increased, and it is difficult to form the contact hole having a fine opening diameter by accurately removing the insulating film. Process problems arise.

  Therefore, the present invention has been made in view of the above problems and the like. For example, a substrate for an electro-optical device that can reduce parasitic capacitance generated between a pixel electrode and a data line and can reduce display defects such as crosstalk. It is another object of the present invention to provide an electro-optical device including such a substrate for an electro-optical device and an electronic apparatus such as a projector.

  In order to solve the above-described problems, an electro-optical device substrate according to the present invention includes a substrate, a conductive film formed on the substrate, to which a predetermined signal is supplied, and the conductive film on the conductive film. A region that is formed so as to partially overlap, is formed between a pixel electrode formed on a pixel on the substrate, the conductive film, and the pixel electrode, and the conductive film and the pixel electrode overlap each other The portion extending in the direction includes a thicker insulating film than the other portions.

  In the electro-optical device substrate according to the present invention, the conductive film is electrically connected to, for example, a circuit unit formed on the substrate, and a predetermined signal is supplied from the circuit unit. The conductive film may be made of a conductive material such as a metal film or a semiconductor film. The pixel electrode is configured using a transparent conductive material such as ITO, for example, and partially overlaps the conductive film on the conductive film. More specifically, the pixel electrode extends from the opening region of the pixel to the non-opening region so as to overlap the conductive film formed in the non-opening region of the pixel, for example.

  The insulating film is formed between the conductive film and the pixel electrode. Such an insulating film may be partially planarized so as not to hinder the formation of various wiring portions and circuit portions formed in the upper and lower layers of the insulating film. The insulating film is formed such that a portion extending in a region where the conductive film and the pixel electrode overlap each other is thicker than the other portions. Therefore, in a region where the conductive film and the pixel electrode overlap each other, parasitic capacitance generated between the conductive film and the pixel electrode is reduced. That is, compared to the case where the insulating film is uniformly formed with the same film thickness as the other portions, the distance between the conductive film and the pixel electrode serving as the capacitance electrode of the parasitic capacitance can be increased, and the distance is increased. Accordingly, it becomes possible to reduce the parasitic capacitance. Note that the insulating film may be a single layer or may have a stacked structure in which a plurality of insulating films are partially stacked.

  In addition, since the other part of the insulating film is thinner than the part extending in the region where the conductive film and the pixel electrode overlap each other, the other part can be dug with high precision, and the contact hole formed with high precision can be formed. Thus, the wiring portion and the like can be electrically connected along the vertical direction on the substrate.

  Therefore, the electro-optical device substrate according to the present invention can reduce display defects such as crosstalk caused by parasitic capacitance generated between the pixel electrode and the conductive film. In addition, since the connection part such as the contact hole can be formed with high precision, each part in the electro-optical device substrate can be electrically and reliably connected.

  In one aspect of the electro-optical device substrate according to the present invention, the conductive film may be a data line that supplies an image signal to the pixel electrode.

  According to the electro-optical device substrate according to the present invention, the potential of the image signal supplied to the data line and the potential of the pixel electrode interfere with each other during the operation of the electro-optical device including the electro-optical device substrate. Can reduce the parasitic capacitance. In addition, it is possible to reduce a delay in writing an image signal that occurs when a shield layer is formed between the pixel electrode and the data line.

  In another aspect of the electro-optical device substrate according to the present invention, the portion extending to the overlapping region is formed on the first insulating film and the first insulating film, and has a dielectric constant lower than that of the first insulating film. The second insulating film may be formed by laminating each other.

  According to this aspect, it occurs between the pixel electrode and the conductive film as compared with the case where the first insulating film having a uniform dielectric constant is formed between the pixel electrode and the conductive film such as the data line. Parasitic capacitance can be reduced. The second insulating film may be formed above or below the first insulating film in order to reduce parasitic capacitance, and may be formed only in a region where the conductive film such as the data line and the pixel electrode overlap each other. The conductive film and the pixel electrode may be partially provided in a region where the conductive film and the pixel electrode overlap each other, or after being formed on the substrate, It may be patterned into a predetermined shape.

  The electro-optical device according to the present invention includes the above-described electro-optical device substrate according to the present invention in order to solve the above problems.

  According to the electro-optical device according to the present invention, since the electro-optical device substrate of the present invention is provided, an electro-optical device having excellent display performance can be provided. Therefore, the electro-optical device according to the present invention can perform high-quality display.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device of the present invention.

  According to the electronic apparatus according to the present invention, since the electro-optical device according to the present invention described above is provided, a projection display device, a mobile phone, an electronic notebook, a word processor, and a viewfinder type capable of high-quality display. Alternatively, various electronic devices such as a monitor direct-view video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. In addition, as an electronic apparatus according to the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

  Hereinafter, embodiments of an electro-optical device substrate, an electro-optical device, and an electronic apparatus according to the present invention will be described with reference to FIGS. 1 to 8. In the following embodiments, a case where the substrate for an electro-optical device of the present invention is applied to a liquid crystal device which is an example of an electro-optical device will be described as an example.

<1: Overall configuration of electro-optical device>
First, the electro-optical device of this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the electro-optical device when the TFT array substrate is viewed from the counter substrate side together with the components formed thereon, and FIG. 2 is a cross-sectional view taken along the line II-II ′ of FIG. In the present embodiment, as an example of an electro-optical device, a TFT active matrix driving type liquid crystal device with a built-in driving circuit is taken as an example.

  1 and 2, in the liquid crystal device 1, a TFT array substrate 10 and a counter substrate 20 are disposed to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are positioned around an image display region 10a that is a pixel region in which a plurality of pixel portions are provided. They are bonded to each other by a sealing material 52 provided in the sealing area.

The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. In the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance between the TFT array substrate 10 and the counter substrate 20 (inter-substrate gap) to a predetermined value is dispersed. In other words, the electro-optical device according to the present embodiment is small and suitable for performing enlarged display for a projector light valve.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the seal material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side. There is a peripheral area located around the image display area 10a. In other words, particularly in the present embodiment, when viewed from the center of the TFT array substrate 10, the distance from the frame light shielding film 53 is defined as the peripheral region.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. The scanning line driving circuit 104 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display area 10 a in this way, a plurality of the pixel lines are covered along the remaining side of the TFT array substrate 10 and covered with the frame light shielding film 53. Wiring 105 is provided.

  Vertical conductive members 106 functioning as vertical conductive terminals between the two substrates are disposed at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corner portions. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20. The counter electrode 21 is electrically connected to a fixed potential LCCOM as shown in FIG. 6 later.

  In FIG. 2, on the TFT array substrate 10, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film are formed on the uppermost layer portion. The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  1 and 2, on the TFT array substrate 10, in addition to the drive circuits such as the data line drive circuit 101 and the scanning line drive circuit 104, the image signal on the image signal line is sampled to obtain data. Sampling circuit that supplies lines, precharge circuit that supplies pre-charge signals of a predetermined voltage level to multiple data lines in advance of image signals, inspection of quality, defects, etc. of the electro-optical device during production or shipment An inspection circuit or the like may be formed.

<2: Configuration in the pixel portion>
Next, the configuration of the pixel portion of the liquid crystal device 1 will be described in detail with reference to FIGS. 3 to 5. FIG. 3 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix forming the image display area of the liquid crystal device 1, and FIG. 4 is formed of data lines, scanning lines, pixel electrodes, and the like FIG. 3 is a plan view of a plurality of pixel groups adjacent to each other on a TFT array substrate. 5 is a cross-sectional view taken along the line VV ′ of FIG. In FIG. 5, the scale of each layer / member is different for each layer / member to have a size that can be recognized on the drawing. In FIG. 5, the TFT array substrate 10 to the alignment film 16 constitute an example of the “substrate for the electro-optical device” according to the present invention.

  In FIG. 3, a pixel electrode 9 a and a TFT 30 are formed in each of a plurality of pixels formed in a matrix that forms an image display area of the liquid crystal device 1. The TFT 30 is electrically connected to the pixel electrode 9a, and performs switching control of the pixel electrode 9a when the liquid crystal device 1 operates. The data line 6a to which the image signal is supplied is electrically connected to the source of the TFT 30. The image signals S1, S2,..., Sn to be written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. May be.

  The scanning line 3a is electrically connected to the gate of the TFT 30, and the liquid crystal device 1 sequentially applies the scanning signals G1, G2,..., Gm to the scanning line 3a in a pulse sequence in this order at a predetermined timing. It is comprised so that it may apply. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,... Supplied from the data line 6a is closed by closing the switch of the TFT 30 serving as a switching element for a certain period. Sn is written at a predetermined timing. A predetermined level of image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is held for a certain period with the counter electrode formed on the counter substrate. The The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the electro-optical device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode.

  Next, a specific configuration of the pixel portion will be described with reference to FIGS. In FIG. 4, on the TFT array substrate 10 of the liquid crystal device 1, a plurality of transparent pixel electrodes 9a (outlined by dotted line portions 9a ′) are provided in a matrix in the X direction and the Y direction. A data line 6a and a scanning line 3a are provided along the vertical and horizontal boundaries of the pixel electrode 9a.

  In the semiconductor layer 1a, the scanning line 3a is arranged so as to face the channel region 1a 'indicated by the hatched region rising to the right in FIG. As described above, the pixel switching TFT 30 is provided at each of the intersections between the scanning line 3a and the data line 6a. In the present embodiment, the scanning line 3 a is electrically connected to the gate electrode 3 a 2 through a contact hole 88 that penetrates the first interlayer insulating film 41.

  The data line 6 a is formed on the base film 42 aa formed using the second interlayer insulating film 42 whose upper surface is flattened as a base, and is connected to the high concentration source region of the TFT 30 through the contact hole 81. Yes. The data line 6a and the inside of the contact hole 81 are made of, for example, an Al (aluminum) -containing material such as Al—Si—Cu or Al—Cu, Al alone, or a multilayer film including an Al layer and a TiN layer. The data line 6a has a function of shielding the TFT 30 from light.

  The storage capacitor 70 includes a lower capacitor electrode 71 as a pixel potential side capacitor electrode connected to the high concentration drain region 1e and the pixel electrode 9a and a part of the upper capacitor electrode 300 as a fixed potential side capacitor electrode. It is formed by being opposed to each other through the film 75.

  As shown in FIGS. 4 and 5, the upper capacitor electrode 300 is provided on the upper side of the TFT 30 as an upper light shielding film (built-in light shielding film) containing, for example, a metal or an alloy. The upper capacitor electrode 300 also functions as a fixed potential side capacitor electrode. The upper capacitor electrode 300 includes at least one of refractory metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum), and Pd (palladium). , Metal simple substance, alloy, metal silicide, polysilicide, and a laminate of these. The upper capacitor electrode 300 may include other metals such as Al (aluminum) and Ag (silver). The upper capacitor electrode 300 may have a multilayer structure in which a first film made of, for example, a conductive polysilicon film and a second film made of a metal silicide film containing a refractory metal or the like are stacked.

  The lower capacitor electrode 71 is made of, for example, a conductive polysilicon film and functions as a pixel potential side capacitor electrode. The lower capacitor electrode 71 functions as a pixel potential side capacitor electrode, and functions as another example of a light absorption layer or an upper light shielding film disposed between the upper capacitor electrode 300 as the upper light shielding film and the TFT 30. Furthermore, the pixel electrode 9a and the high-concentration drain region 1e of the TFT 30 have a function of relay connection. However, the lower capacitive electrode 71 may also be composed of a single layer film or a multilayer film containing a metal or an alloy, like the upper capacitive electrode 300.

  The dielectric film 75 disposed between the lower capacitor electrode 71 and the upper capacitor electrode 300 as a capacitor electrode is, for example, a silicon oxide film such as an HTO (High Temperature Oxide) film, an LTO (Low Temperature Oxide) film, or a nitride. It is composed of a silicon film or the like.

  The upper capacitor electrode 300 extends from the image display region 10a where the pixel electrode 9a is disposed to the periphery thereof, and is electrically connected to a constant potential source to be a fixed potential.

  The lower light-shielding film 11a provided in a grid pattern below the TFT 30 via the base insulating film 12 shields the channel region 1a ′ of the TFT 30 and its surroundings from the return light that enters the device from the TFT array substrate 10 side. To do. Similarly to the upper capacitor electrode 300, the lower light-shielding film 11a includes, for example, a simple metal, an alloy, a metal silicide, including at least one of refractory metals such as Ti, Cr, W, Ta, Mo, and Pd. It is made of polysilicide or a laminate of these.

  In addition to the function of interlayer insulating the TFT 30 from the lower light-shielding film 11a, the base insulating layer 12 is formed on the entire surface of the TFT array substrate 10, thereby remaining rough after polishing the surface of the TFT array substrate 10 or after cleaning. It has a function of preventing deterioration of the characteristics of the pixel switching TFT 30 due to dirt or the like. The pixel electrode 9a is electrically connected to the high concentration drain region 1e in the semiconductor layer 1a through the contact holes 83 and 85 by relaying the lower capacitor electrode 71.

  As shown in FIGS. 4 and 5, the liquid crystal device 1 includes a transparent TFT array substrate 10 and a transparent counter substrate 20 disposed to face the TFT array substrate 10. The TFT array substrate 10 is made of, for example, a quartz substrate, a glass substrate, or a silicon substrate, and the counter substrate 20 is made of, for example, a glass substrate or a quartz substrate.

  A pixel electrode 9a is provided on the TFT array substrate 10, and an alignment film 16 that has been subjected to a predetermined alignment process such as a rubbing process is provided above the pixel electrode 9a. For example, the pixel electrode 9a is made of a transparent conductive film such as an ITO (Indium Tin Oxide) film, and the alignment film 16 is made of an organic film such as a polyimide film.

  A counter electrode 21 is provided on the entire surface of the counter substrate 20, and an alignment film 22 subjected to a predetermined alignment process such as a rubbing process is provided below the counter electrode 21. The counter electrode 21 is made of a transparent conductive film such as an ITO film. The alignment film 22 is made of an organic film such as a polyimide film.

  The counter substrate 20 may be provided with a lattice-shaped or striped light-shielding film. By adopting such a configuration, together with the upper light shielding film provided as the upper capacitor electrode 300, it is more reliable to prevent the incident light from entering the channel region 1a ′ or its periphery from the TFT array substrate 10 side. Can be prevented.

  A liquid crystal layer 50 is formed between the TFT array substrate 10 and the counter substrate 20 that are configured as described above and are arranged so that the pixel electrode 9a and the counter electrode 21 face each other. The liquid crystal layer 50 takes a predetermined alignment state by the alignment films 16 and 22 in a state where an electric field from the pixel electrode 9a is not applied.

  In FIG. 5, the pixel switching TFT 30 has an LDD (Lightly Doped Drain) structure, and includes a gate electrode 3a2, a channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, and a scanning line. An insulating film 2 including a gate insulating film that insulates 3a from the semiconductor layer 1a, a low concentration source region 1b and a low concentration drain region 1c, a high concentration source region 1d, and a high concentration drain region 1e are provided. The low-concentration source region 1b, the low-concentration drain region 1c, the high-concentration source region 1d, and the high-concentration drain region 1e constitute an impurity region of the semiconductor layer 1a and are formed in mirror symmetry on both sides of the channel region 1a ′. Yes.

  The gate electrode 3a2 is formed of a conductive film such as a polysilicon film, and is provided on the channel region 1a ′ via the insulating film 2 so as not to overlap the low concentration source region 1b and the low concentration drain region 1c. . Therefore, in the TFT 30, an offset between the high concentration source region 1d and the high concentration drain region 1e and the first gate electrode 3a1 is sufficiently secured.

  Note that the edge of the gate electrode 3a2 overlaps the boundary between the lightly doped source region 1b and the lightly doped drain region 1c and the channel region 1a ′ in plan view, and the lightly doped source region 1b and the lightly doped drain region 1c The parasitic capacitance generated between the first gate electrode 3a1 and the first gate electrode 3a1 is reduced. As a result, the TFT 30 transistor can operate at high speed, and the display performance of the liquid crystal device 1 is enhanced.

  In addition, in the liquid crystal device 1, the low-concentration source region 1 b and the low-concentration drain are effectively provided by the upper capacitor electrode 300 formed on the gate electrode 3 a 2 so as to cover the TFT 30 as compared with the case where the light is shielded only by the gate electrode 3 a 2. The region 1c can be shielded from light.

  As described above, according to the liquid crystal device 1, it is possible to reduce defects caused when displaying an image such as flicker using the TFT 30 with reduced light leakage current, and to display an image with high quality. In addition, since the TFT 30 has an LDD structure, the off-current flowing through the low-concentration source region 1b and the low-concentration drain region 1c is reduced when the TFT 30 is not operating, and the on-current flowing when the TFT 30 is operating is reduced. Is suppressed. Therefore, according to the liquid crystal device 1, it is possible to display an image with high quality by utilizing the advantage of the LDD structure and the fact that light leakage current hardly flows.

  On the scanning line 3a, a first interlayer insulating film 41 is formed in which a contact hole 81 leading to the high concentration source region 1d and a contact hole 83 leading to the high concentration drain region 1e are respectively opened.

  A lower capacitor electrode 71 and an upper capacitor electrode 300 are formed on the first interlayer insulating film 41, and a second interlayer insulating film 42 in which contact holes 81 and 85 are respectively formed is formed thereon. ing.

  The second interlayer insulating film 42 in the present embodiment is made of, for example, a BPSG film, and the upper surface is flattened through a fluidized state by heating. That is, a step is formed on the upper surface during the film formation due to the existence of the storage capacitor 70, the TFT 30, the scanning line 3a, and further the base light shielding film 11a on the lower layer side. The unevenness due to the steps is leveled.

  In FIG. 5, the upper surface of the second interlayer insulating film 42 is formed flat, but the upper surface of the second interlayer insulating film 42 is not a completely flat surface, and a stepped portion caused by the scanning line 3 a and the like is left. May be. According to such a step portion, it is also possible to reduce a horizontal electric field between pixels generated during driving.

  Further, the third interlayer insulating film 43, which is an example of the “insulating film” according to the present invention, in which the contact hole 85 is formed so as to cover the entire surface of the second interlayer insulating film 42 from above the data line 6a, It is formed of a BPSG film. The pixel electrode 9 a and the alignment film 16 are provided on the upper surface of the third interlayer insulating film 43.

  The third interlayer insulating film 43 is formed between the data line 6a and the pixel electrode 9a, and is formed so that a portion extending to the region R where the data line 6a and the pixel electrode 9a overlap each other is thicker than the other portions. Has been. More specifically, a convex portion 43 a is formed as a portion extending to the region R in the third interlayer insulating film 43. According to such a convex portion 43a, the distance between the pixel electrode 9a and the data line 6a can be increased as compared with the case where the third interlayer insulating film 43 is formed as a uniform insulating film, as shown in FIG. As described above, the parasitic capacitance C generated using the pixel electrode 9a and the data line 6a as the capacitance electrodes can be reduced.

In addition, a contact hole 85 for electrically connecting the high-concentration drain region 1e of the TFT 30 and the pixel electrode 9a is formed in a portion not overlapping the region R of the third interlayer insulating film 43. Since the third interlayer insulating film 43 is only partially thick in the region R, the film thickness of the other portions is thinner than that in the region R. Accordingly, even if the contact hole 85 is formed by deeply digging the third interlayer insulating film 43, the contact hole 85 that electrically connects the pixel electrode 9a and the lower capacitor electrode 71 can be formed with a small opening diameter.
Therefore, it is possible to reliably establish electrical connection in the vertical direction on the TFT array substrate 10 through the contact hole 85 formed with high accuracy.

  Therefore, according to the liquid crystal device according to the present embodiment, it is possible to reduce the parasitic capacitance generated when the potential of the image signal supplied to the data line 6a and the potential of the pixel electrode 9a interfere with each other during the operation of the liquid crystal device. . In addition, it is possible to reduce a delay in writing an image signal that occurs when a shield layer is formed between the pixel electrode 9a and the data line 6a. Display defects such as crosstalk that occur during operation of the liquid crystal device 1 can be reduced. In addition, since connection portions such as contact holes can be formed with high accuracy, the respective portions formed on the TFT array substrate 10 can be electrically connected reliably.

  In the present embodiment, the data line 6a overlapping the pixel electrode 9a has been described as an example of the “conductive film” according to the present invention. However, the “conductive film” according to the present invention is not limited to the data line 6a. Alternatively, any wiring portion formed in a non-opening region that separates the pixel opening regions from each other, or any element portion that overlaps the pixel electrode 9a in a planar manner to generate parasitic capacitance may be used. By reducing the parasitic capacitance generated between the conductive film and the pixel electrode, the display quality of the entire electro-optical device can be improved.

<3: Modification>
Next, a modification of the electro-optical device substrate according to the present embodiment will be described with reference to FIG. FIG. 7 is a partial cross-sectional view of the electro-optical device substrate according to the present example. In FIG. 7, parts common to the liquid crystal device 1 described above are denoted by common reference numerals, and detailed description thereof is omitted.

  In FIG. 7, the third interlayer insulating film 43 has a first insulating film 43 b and a second insulating film 43 c in a portion extending to the region R. The first insulating film 43b extends over the entire TFT array substrate 10 so as to cover the second interlayer insulating film 42 and the data line 6a. The second insulating film 43c is formed in a convex shape on the first insulating film 43b in the region R, and has a dielectric constant lower than that of the first insulating film.

  The second insulating film 43c is generated between the pixel electrode 9a and the data line 6a as compared with the case where the first insulating film 43b having a uniform dielectric constant is formed between the pixel electrode 9a and the data line 6a. Parasitic capacitance can be further reduced. In order to reduce parasitic capacitance, the second insulating film 43c is formed above or below the first insulating film 43b, and is formed only in the region R where the data line 6a and the pixel electrode 9a overlap each other. Also good. As shown in FIG. 7, the data line 6a and the pixel electrode 9a may be partially provided in the overlapping region R, or after being formed in a certain range on the first insulating film 43b, It may be patterned into a predetermined shape so as to remain.

(Electronics)
Next, the case where the above-described liquid crystal device is applied to various electronic devices will be described.

  First, a projector using this liquid crystal device as a light valve will be described. FIG. 8 is a plan view showing a configuration example of the projector. As shown in FIG. 8, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the external circuit (not shown) to the external connection terminal 102, respectively. It is. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In this dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Accordingly, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R, 1110B.

  Since light corresponding to the primary colors R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

FIG. 3 is a plan view of the electro-optical device according to the present embodiment as viewed from the counter substrate side. It is II-II 'sectional drawing of FIG. 4 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms an image display region of the electro-optical device according to the embodiment. 4 is a plan view of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes, and the like are formed in the electro-optical device according to the embodiment. FIG. It is VV 'sectional drawing of FIG. 3 is a circuit diagram illustrating a circuit configuration of a pixel portion including a parasitic capacitance C. FIG. FIG. 10 is a partial cross-sectional view of a modification of the electro-optical device substrate according to the embodiment. It is a top view of the projector which is an example of the electronic device which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 10 ... TFT array substrate, 9a ... Pixel electrode, 6a ... Data line, 43 ... 3rd interlayer insulation film, 43a ... Projection part, 43b ... 1st insulating film, 43c ... 2nd insulating film

Claims (5)

A substrate,
A conductive film formed on the substrate and supplied with a predetermined signal;
A pixel electrode formed on the conductive film so as to partially overlap the conductive film, and formed on a pixel on the substrate;
An electro-optical device comprising: an insulating film formed between the conductive film and the pixel electrode, wherein a portion extending in a region where the conductive film and the pixel electrode overlap with each other is thicker than other portions. Device substrate. The electro-optical device substrate according to claim 1, wherein the conductive film is a data line that supplies an image signal to the pixel electrode. The portion extending to the overlapping region is formed by laminating a first insulating film and a second insulating film formed on the first insulating film and having a dielectric constant lower than that of the first insulating film. The substrate for an electro-optical device according to claim 1, wherein the substrate is an electro-optical device. An electro-optical device comprising the electro-optical device substrate according to claim 1. An electronic apparatus comprising the electro-optical device according to claim 4.

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